My problem is
i have this JSON file:
and i have to save it in a list but when i try to print the first element of the list I get a System.ArgumentOutOfRangeException, as if my list is empty. this is my code:
JavaScriptSerializer ser = new JavaScriptSerializer();
Causali o = new Causali();
List<CausaliList> lista = new List<CausaliList>();
WebRequest causali = (HttpWebRequest)WebRequest.Create("http://trackrest.cgestmobile.it/causali");
WebResponse risposta = (HttpWebResponse)CreateCausaliRequest(causali).GetResponse();
Stream data = risposta.GetResponseStream();
StreamReader Leggi = new StreamReader(data);
string output = Leggi.ReadToEnd();
lista = ser.Deserialize<List<CausaliList>>(output);
lst2.Items.Add(lista[0]);
and these are my two class for the saves:
class Causali
{
public int id;
public string causaliname;
public string identificationcode;
public string expired;
}
and
class CausaliList
{
public Causali causali;
}
can you help me solve it?
please try this as your root object:
public class CausaliList
{
public List<Causali> causali { get; set; }
}
then deserilize your object like this:
lista = ser.Deserialize<CausaliList>(output);
finally you can access to list like this:
lst2.Items.Add(lista.causali[0]);
Note: i strongly recommend to use json.NET.
To deserialize the code in c#:
Lets assume you have data in var getContent then you may use this:
dynamic getDesearilize = JsonConvert.DeserializeObject(getContent);
Related
I have following method, which is read JSON from the directory and de-serialize the JSON into C# class object.
public static JObject readJson(string fileName)
{
string JSON = "";
List<string> keyList = new List<string>();
using (StreamReader r = new StreamReader(fileName))
{
JSON = r.ReadToEnd();
}
JObject parsed = JObject.Parse(JSON);
var name = parsed["2"];
Numbers deserializedClass = JsonConvert.DeserializeObject<Numbers>(name.ToString());
return parsed;
}
Here you can see, I'm used class called Numbers. I'm passing separate JSON file's name to the above method, based on that I also need to pass Class to convert JSON into C# object. How can I pass class to the above method as a generic? then I think I can modify this line,
var deserializedClass = JsonConvert.DeserializeObject<AnyClass>(name.ToString());
is it possible to do?
try this:
public static JObject readJson<T>(string fileName)
{
string JSON = "";
List<string> keyList = new List<string>();
using (StreamReader r = new StreamReader(fileName))
{
JSON = r.ReadToEnd();
}
JObject parsed = JObject.Parse(JSON);
var name = parsed["2"];
Numbers deserializedClass = JsonConvert.DeserializeObject<T>(name.ToString());
return parsed;
}
https://learn.microsoft.com/en-us/dotnet/standard/generics/
https://learn.microsoft.com/en-us/dotnet/csharp/fundamentals/types/generics
This method uses Generics and will take the Type you specify and return the object of that type.
public static T readJson<T>(string fileName)
{
var JSON = string.Empty;
using (var r = new StreamReader(fileName))
{
JSON = r.ReadToEnd();
}
var parsed = JObject.Parse(JSON);
var name = parsed["2"];
var deserializedClass = JsonConvert.DeserializeObject<T>(name.ToString());
return deserializedClass;
}
Usage:
var resultObject = readJson<Number>(fileName);
https://learn.microsoft.com/en-us/dotnet/csharp/fundamentals/types/generics
I want to serialize some json data I get from the web to classes and use the data, so I went to http://json2csharp.com/ and turned the json as below
json: [{"line_descr":"\u03a0\u0395\u0399\u03a1\u0391\u0399\u0391\u03a3 -
\u0392\u039f\u03a5\u039b\u0391","line_descr_eng":"PEIRAIAS - VOYLA"}]
To this class:
public class RootObject
{
public string line_descr { get; set; }
public string line_descr_eng { get; set; }
}
This is my code:
class LineName
{
public async static Task<RootObject> GetLineName(int linecode)
{
var http = new HttpClient();
var response = await http.GetAsync("http://telematics.oasa.gr/api/?act=getLineName&p1=962");
var result = await response.Content.ReadAsStringAsync();
var serializer = new DataContractJsonSerializer(typeof(RootObject));
var ms = new MemoryStream(Encoding.UTF8.GetBytes(result));
var data = (RootObject)serializer.ReadObject(ms);
return data;
}
}
[DataContract]
public class RootObject
{
[DataMember]
public string line_descr { get; set; }
[DataMember]
public string line_descr_eng { get; set; }
}
private async void Button_Click(object sender, RoutedEventArgs e)
{
RootObject myLine = await LineName.GetLineName(92);
ResultTextBlock.Text = myLine.line_descr_eng;
}
So when I try to get the data and display it in my textblock I get the error: line_descr_eng is null.
Can someone point where the fault is ? since the line_descr_eng should be
PEIRAIAS - VOYLA but mine is null and after a lot of searching I cant find where the fault is.
Your json is an array, not an object, and you should deserialize it into an array.
public async static Task<RootObject[]> GetLineName(int linecode)
{
var http = new HttpClient();
var response = await http.GetAsync("http://telematics.oasa.gr/api/?act=getLineName&p1=962");
var result = await response.Content.ReadAsStringAsync();
var serializer = new DataContractJsonSerializer(typeof(RootObject[]));
var ms = new MemoryStream(Encoding.UTF8.GetBytes(result));
var data = (RootObject[])serializer.ReadObject(ms);
return data;
}
//...
var myLines = await LineName.GetLineName(92);
var myLine = myLines.FirstOrDefault();
Also you don't need a memory stream, you can read stream from the http response
var result = await response.Content.ReadAsStreamAsync();
You simple can use the JavaScriptSerializer class instead of DataContractJsonSerializer like this:
Replace:
var serializer = new DataContractJsonSerializer(typeof(RootObject));
var ms = new MemoryStream(Encoding.UTF8.GetBytes(result));
var data = (RootObject)serializer.ReadObject(ms);
with this:
var ser = new JavaScriptSerializer();
var test = ser.Deserialize<List<RootObject>>(json);
If you cannot find JavaScriptSerializer, then you have to do the simple following steps:
Right click References and do Add Reference, then from Assemblies->Framework select System.Web.Extensions.
Now you should be able to add the following to your class file:
using System.Web.Script.Serialization;
Cited from: https://stackoverflow.com/a/15391388/5056173
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using Facebook;
using Newtonsoft.Json;
namespace facebook
{
class Program
{
static void Main(string[] args)
{
var client = new FacebookClient(acc_ess);
dynamic result = client.Get("fql", new { q = "select target_id,target_type from connection where source_id = me()"});
string jsonstring = JsonConvert.SerializeObject(result);
//jsonstring {"data":[{"target_id":9503123,"target_type":"user"}]}
List<RootObject> datalist = JsonConvert.DeserializeObject<List<RootObject>>(jsonstring);
}
public class Datum
{
public Int64 target_id { get; set; }
public string target_type { get; set; }
}
public class RootObject
{
public List<Datum> data { get; set; }
}
}
}
Cannot deserialize the current JSON object (e.g. {"name":"value"})
into type
'System.Collections.Generic.List`1[facebook.Program+RootObject]'
because the type requires a JSON array (e.g. [1,2,3]) to deserialize
correctly. To fix this error either change the JSON to a JSON array
(e.g. [1,2,3]) or change the deserialized type so that it is a normal
.NET type (e.g. not a primitive type like integer, not a collection
type like an array or List) that can be
I looked at other posts.
My json looks like this:
{"data":[{"target_id":9503123,"target_type":"user"}]}
To make it clear, in addition to #SLaks' answer, that meant you need to change this line :
List<RootObject> datalist = JsonConvert.DeserializeObject<List<RootObject>>(jsonstring);
to something like this :
RootObject datalist = JsonConvert.DeserializeObject<RootObject>(jsonstring);
As the error message is trying very hard to tell you, you can't deserialize a single object into a collection (List<>).
You want to deserialize into a single RootObject.
Can you try to change your json without data key like below?
[{"target_id":9503123,"target_type":"user"}]
That happened to me too, because I was trying to get an IEnumerable but the response had a single value. Please try to make sure it's a list of data in your response. The lines I used (for api url get) to solve the problem are like these:
HttpResponseMessage response = await client.GetAsync("api/yourUrl");
if (response.IsSuccessStatusCode)
{
IEnumerable<RootObject> rootObjects =
awaitresponse.Content.ReadAsAsync<IEnumerable<RootObject>>();
foreach (var rootObject in rootObjects)
{
Console.WriteLine(
"{0}\t${1}\t{2}",
rootObject.Data1, rootObject.Data2, rootObject.Data3);
}
Console.ReadLine();
}
Hope It helps.
The real problem is that you are using dynamic return type in the FacebookClient Get method. And although you use a method for serializing, the JSON converter cannot deserialize this Object after that.
Use insted of:
dynamic result = client.Get("fql", new { q = "select target_id,target_type from connection where source_id = me()"});
string jsonstring = JsonConvert.SerializeObject(result);
something like that:
string result = client.Get("fql", new { q = "select target_id,target_type from connection where source_id = me()"}).ToString();
Then you can use DeserializeObject method:
var datalist = JsonConvert.DeserializeObject<List<RootObject>>(result);
Hope this helps.
public partial class tree
{
public int id { get; set; }
public string name { get; set; }
public string sciencename { get; set; }
public int familyid { get; set; }
}
private async void PopulateDataGridView()
{
//For Single object response
tree treeobj = new tree();
treeobj = JsonConvert.DeserializeObject<tree>(Response);
//For list of object response
List<tree> treelistobj = new List<tree>();
treelistobj = JsonConvert.DeserializeObject<List<tree>>(Response);
//done
}
I am trying to search all favourite Filters (JIRA) from the actual User using c# HttpWebRequest and Rest-Api. I am still able to read Issues but the filters aren't working.
Reading Issues works as follows:
For example I have this URL to get all Issues from project IT:
http://jira-test.myServer.de/rest/api/2/search?jql=project=%22IT%22
I am using DataContractJsonSerializer to swap the JSON Response to C#-Objects.
From this class I am getting an object after Serialization:
[DataContract]
internal class Kopf
{
[DataMember]
public string startAt = string.Empty;
[DataMember]
public string maxResults = string.Empty;
[DataMember]
public string total = string.Empty;
[DataMember]
public Issues[] issues = null;
}
The first lines of JSON are looking like this:
{"expand":"schema,names","startAt":0,"maxResults":50,"total":23044,"issues":[{"expand":"operations,editmeta,changelog,transitions,renderedFields","id":"40000","self":"http://jira-test.myServer.de/rest/api/2/issue/40000","key":"IT-23237","fields":
So I can't understand why the following isn't working for me:
This URL give me the right JSON in Browser:
http://jira-test.myServer.de/rest/api/2/filter/favourite
First lines of JSON:
[{"self":"http://jira-test.myServer.de/rest/api/2/filter/10119","id":"10119","name":"Aktiv","description":"Alle Aufgaben die gerade aktiv von mir bearbeitet werden.","owner":{"self":"http://jira-test.myServer.de/rest/api/2/user?username=sb9923","key":"sb9923","name":"sb9923","avatarUrls":{"16x16":"http://jira-test.myServer.de/secure/useravatar?
And here is my Object which I want to serialize:
[DataContract]
internal class FilterData
{
[DataMember]
public FilterKopf[] filter = null;
}
[DataContract]
internal class FilterKopf
{
[DataMember]
public string id = string.Empty;
[DataMember]
public string name = string.Empty;
[DataMember]
public string description = string.Empty;
[DataMember]
public string jql = string.Empty;
}
I don't get any Exception or something but the FilterKopf Array in the FilterData-Object is always null.
I hope someone can help me with this. I think my C#-Class is the problem because the JSON seems fine and my browser gives the right output.
If I understand right your problem is that the result contains an array of "Filter" objects but you want to deserialize it as a simple object containing the array. So all you need is to deserialize the stream as FilterKopf[] instead of FilterData.
I created a simple request based on this answer (I modified it slightly, e.g. not POST but GET)
public class JiraTest
{
internal IEnumerable<FilterKopf> GetFavouriteFilters()
{
string url = "http://jira-test.myserver.de/rest/api/2/filter/favourite";
var httpWebRequest = (HttpWebRequest)WebRequest.Create(url);
httpWebRequest.ContentType = "application/json";
httpWebRequest.Method = "GET";
httpWebRequest.Headers["Authorization"] = "Basic " + Convert.ToBase64String(Encoding.Default.GetBytes("YOUR_USERNAME:YOUR_PASSWORD"));
var httpResponse = (HttpWebResponse)httpWebRequest.GetResponse();
DataContractJsonSerializer serializer = new DataContractJsonSerializer(typeof(FilterKopf[]));
var filterKoepfe = (FilterKopf[])serializer.ReadObject(httpResponse.GetResponseStream());
return filterKoepfe;
}
}
[DataContract]
internal class FilterKopf
{
[DataMember]
public string id = string.Empty;
[DataMember]
public string name = string.Empty;
[DataMember]
public string description = string.Empty;
[DataMember]
public string jql = string.Empty;
}
With my own account and with my access to our Jira server the results really reflected my favourite filters.
Update
As a second chance, try to use Json.NET instead of DataContractJsonSerializer. Add to the project through NuGet, and replace the two rows of deserialization to these:
FilterKopf[] filterKoepfe = null;
using (Stream stream = httpResponse.GetResponseStream())
using (StreamReader reader = new StreamReader(stream, Encoding.UTF8))
{
string jsonResponse = reader.ReadToEnd();
filterKoepfe = Newtonsoft.Json.JsonConvert.DeserializeObject<FilterKopf[]>(jsonResponse);
}
Let's take a look what this does.
I'm trying to deserialize a Facebook friend's Graph API call into a list of objects. The JSON object looks like:
{"data":[{"id":"518523721","name":"ftyft"},
{"id":"527032438","name":"ftyftyf"},
{"id":"527572047","name":"ftgft"},
{"id":"531141884","name":"ftftft"},
{"id":"532652067","name"...
List<EFacebook> facebooks = new JavaScriptSerializer().Deserialize<List<EFacebook>>(result);
It's not working, because the primitive object is invalid. How can I deserialize this?
You need to create a structure like this:
public class Friends
{
public List<FacebookFriend> data {get; set;}
}
public class FacebookFriend
{
public string id {get; set;}
public string name {get; set;}
}
Then you should be able to do:
Friends facebookFriends = new JavaScriptSerializer().Deserialize<Friends>(result);
The names of my classes are just an example. You should use proper names.
Adding a sample test:
string json =
#"{""data"":[{""id"":""518523721"",""name"":""ftyft""}, {""id"":""527032438"",""name"":""ftyftyf""}, {""id"":""527572047"",""name"":""ftgft""}, {""id"":""531141884"",""name"":""ftftft""}]}";
Friends facebookFriends = new System.Web.Script.Serialization.JavaScriptSerializer().Deserialize<Friends>(json);
foreach(var item in facebookFriends.data)
{
Console.WriteLine("id: {0}, name: {1}", item.id, item.name);
}
Produces:
id: 518523721, name: ftyft
id: 527032438, name: ftyftyf
id: 527572047, name: ftgft
id: 531141884, name: ftftft
Sometimes I prefer dynamic objects:
public JsonResult GetJson()
{
string res;
WebClient client = new WebClient();
// Download string
string value = client.DownloadString("https://api.instagram.com/v1/users/000000000/media/recent/?client_id=clientId");
// Write values
res = value;
dynamic dyn = JsonConvert.DeserializeObject(res);
var lstInstagramObjects = new List<InstagramModel>();
foreach(var obj in dyn.data)
{
lstInstagramObjects.Add(new InstagramModel()
{
Link = (obj.link != null) ? obj.link.ToString() : "",
VideoUrl = (obj.videos != null) ? obj.videos.standard_resolution.url.ToString() : "",
CommentsCount = int.Parse(obj.comments.count.ToString()),
LikesCount = int.Parse(obj.likes.count.ToString()),
CreatedTime = new System.DateTime(1970, 1, 1, 0, 0, 0, 0).AddSeconds((double.Parse(obj.created_time.ToString()))),
ImageUrl = (obj.images != null) ? obj.images.standard_resolution.url.ToString() : "",
User = new InstagramModel.UserAccount()
{
username = obj.user.username,
website = obj.user.website,
profile_picture = obj.user.profile_picture,
full_name = obj.user.full_name,
bio = obj.user.bio,
id = obj.user.id
}
});
}
return Json(lstInstagramObjects, JsonRequestBehavior.AllowGet);
}
A great way to automatically generate these classes for you is to copy your JSON output and throw it in here:
http://json2csharp.com/
It will provide you with a starting point to touch up your classes for deserialization.
Very easily we can parse JSON content with the help of dictionary and JavaScriptSerializer. Here is the sample code by which I parse JSON content from an ashx file.
var jss = new JavaScriptSerializer();
string json = new StreamReader(context.Request.InputStream).ReadToEnd();
Dictionary<string, string> sData = jss.Deserialize<Dictionary<string, string>>(json);
string _Name = sData["Name"].ToString();
string _Subject = sData["Subject"].ToString();
string _Email = sData["Email"].ToString();
string _Details = sData["Details"].ToString();
Newtonsoft.JSON is a good solution for these kind of situations. Also Newtonsof.JSON is faster than others, such as JavaScriptSerializer, DataContractJsonSerializer.
In this sample, you can the following:
var jsonData = JObject.Parse("your JSON data here");
Then you can cast jsonData to JArray, and you can use a for loop to get data at each iteration.
Also, I want to add something:
for (int i = 0; (JArray)jsonData["data"].Count; i++)
{
var data = jsonData[i - 1];
}
Working with dynamic object and using Newtonsoft serialize is a good choice.
I agree with Icarus (would have commented if I could),
but instead of using a CustomObject class,
I would use a Dictionary (in case Facebook adds something).
private class MyFacebookClass
{
public IList<IDictionary<string, string>> data { get; set; }
}
or
private class MyFacebookClass
{
public IList<IDictionary<string, object>> data { get; set; }
}
Serialization:
// Convert an object to JSON string format
string jsonData = JsonConvert.SerializeObject(obj);
Response.Write(jsonData);
Deserialization::
To deserialize a dynamic object
string json = #"{
'Name': 'name',
'Description': 'des'
}";
var res = JsonConvert.DeserializeObject< dynamic>(json);
Response.Write(res.Name);
If you're using .NET Core 3.0, you can use System.Text.Json (which is now built-in) to deserialize JSON.
The first step is to create classes to model the JSON. There are many tools which can help with this, and some of the answers here list them.
Some options are http://json2csharp.com, http://app.quicktype.io, or use Visual Studio (menu Edit → Paste Special → Paste JSON as classes).
public class Person
{
public string Id { get; set; }
public string Name { get; set; }
}
public class Response
{
public List<Person> Data { get; set; }
}
Then you can deserialize using:
var people = JsonSerializer.Deserialize<Response>(json);
If you need to add settings, such as camelCase handling, then pass serializer settings into the deserializer like this:
var options = new JsonSerializerOptions() { PropertyNamingPolicy = JsonNamingPolicy.CamelCase };
var person = JsonSerializer.Deserialize<Response>(json, options);
You can use this extensions
public static class JsonExtensions
{
public static T ToObject<T>(this string jsonText)
{
return JsonConvert.DeserializeObject<T>(jsonText);
}
public static string ToJson<T>(this T obj)
{
return JsonConvert.SerializeObject(obj);
}
}
Here is another site that will help you with all the code you need as long as you have a correctly formated JSON string available:
https://app.quicktype.io/